function call操作符的重载

#include<iostream>
using namespace std;

template<typename T>
struct plus1
{
        T operator()(const T& x,const T& y) const
        {
                return x+y;
        }
};

template<typename T>
struct minus1
{
        T operator()(const T& x,const T& y) const
        {
                return x-y;
        }
};

int main()
{
        plus1<int> t1;
        minus1<int> t2;
        
        cout<<t1(10,25)<<endl;
        cout<<t2(10,25)<<endl;

        return 0;
}